Fluorescent sensing of pyrophosphate anion in synovial fluid based on DNA-attached magnetic nanoparticles

Abstract

In this work, a new fluorescent method for sensitive detection of pyrophosphate anion (P2O7(4-), PPi) in the synovial fluid was developed using fluorophore labeled single-stranded DNA-attached Fe3O4 NPs. The sensing approach is based on the strong affinity of PPi to Fe3O4 NPs and highly efficient fluorescent quenching ability of Fe3O4 NPs for fluorophore labeled single-stranded DNA. In the presence of PPi, the fluorescence would enhance dramatically due to desorption of fluorophore labeled single-stranded DNA from the surface of Fe3O4 NPs, which allowed the analysis of PPi in a very simple manner. The proposed sensing system allows for the sensitive determination of PPi in the range of 2.0 × 10(-7)-4 × 10(-6)M with a detection limit of 76 nM. Importantly, the protocol exhibits excellent selectivity for the determination of PPi over other phosphate-containing compounds. The method was successfully applied to the determination of PPi in the synovial fluid, which suggests our proposed method has great potential for diagnostic purposes.

Keywords: Fe(3)O(4) nanoparticles; Fluorescent sensing; Fluorophore labeled single-stranded DNA; Pyrophosphate anion; Synovial fluid.